In the above-referenced Merz et al. U.S. Pat. No. 5,304,590, methods are disclosed for compounding polyacrylonitrile with certain plasticizers such as ethylene carbonate and/or propylene carbonate to provide extrudable polyacrylonitrile compounds or compositions suitable for making films and other extruded products. While the methods disclosed in the Merz et al. disclosure are commercially attractive processes which provide extrudable polyacrylonitrile compositions, it is the objective of the present invention to provide yet further improved methods for providing melt extrudable polyacrylonitrile compositions.